Price Cycles and Asymmetric Price Transmission in the U.S. Pork Market

Economists have proposed several plausible explanations for observed price transmission asymmetries in commodity markets. Unfortunately, the econometric methods commonly used in such studies cannot empirically distinguish pricing behavior under the competing theories. We argue that the theories may be classified by firm responses to high- and low-frequency price cycles and use Engle's band spectrum regression to test the symmetry of high- and low-frequency cycles in weekly pork prices. The findings indicate that changes in wholesale prices are asymmetrically transmitted to retail prices in relatively low-frequency cycles, which does not support search costs and other high-frequency explanations. Conversely, wholesale pork prices asymmetrically adjust to changes in farm prices at all frequencies.     

食品安全丑闻报道与产销价格传导——基于中国猪肉市场的经验研究

本文利用主流媒体对猪肉质量安全事件的新闻报道构造食品安全丑闻报道指数,首次从媒体报道视角分析食品安全丑闻对中国猪肉供应链产销价格传导的影响。平滑转换误差修正模型检验结果表明:(1)食品安全丑闻报道是决定产销价格传导关系的门槛变量,当食品安全丑闻报道指数处于门槛值以内时,产销价格传导表现为线性关系,超出门槛值以后,则表现为非线性关系,但更多时候表现为非线性关系;(2)食品安全丑闻报道对产销价格具有非对称冲击效应,生猪价格比猪肉价格对冲击的反应程度更大、持续时间更长。这种非对称冲击效应不仅会打破产销价格波动的固有规律,也会加剧供应链上福利分配不均衡,处于弱势地位的养殖户更容易遭受福利损失。进一步采用向量自回归模型进行脉冲响应分析,结果仍然支持上述结论。     

土地供应管制、住房供给弹性与房价周期波动

研究目的:分析土地供应管制通过住房供给弹性渠道对房价周期波动的影响。研究方法:理论分析,计量检验。研究结果:(1)土地供应管制影响房价波动的渠道是:土地供应管制的宽松和收紧通过供地规模、用地成本以及市场预期影响住房供给弹性,再经由供求关系和投机效应的传导影响房价波动。(2)土地供应管制可以解释45%的城市间住房供给弹性差异;地方政府不同松紧程度的策略性供地行为导致住房供给弹性与城市经济发达程度负相关,中央偏向中西部的土地配额管制政策导致东部城市住房供给弹性低于中西部城市。(3)住房供给弹性决定了房价周期波动,并具有非对称性效应:在市场景气繁荣阶段,供给弹性越小,房价涨幅就越大;在市场不景气阶段,房价跌幅与供给弹性的关系存在方向上的不确定性。研究结论:土地和住房领域供给侧改革的一个重点是改革供地制度和调整供地政策,使土地供应与住房需求在时空维度上相匹配,将有利于熨平房价波动,降低市场风险。     

Price Transmission in Nigerian Food Security Crop Markets

This paper comprehensively examines price transmission from world, neighbour country, and internal commercial hub markets to Nigerian urban markets, as well as from urban to rural markets within the country, for seven key food security crops (maize, millet, sorghum, rice, cassava, yams and cowpeas). There are three key findings: (i) tradability matters for price transmission, but tradability varies across crops and regions. The strongest international linkages are with neighbouring countries. Rice price transmission is high across all markets, while coarse grain price correspondence is low with world prices but high with neighbour country market prices; (ii) our results imply that local conditions matter for price transmission, and are relatively more important than trade for some crops (e.g. yams, cassava) than others (e.g. imported rice, maize); (iii) larger than expected long‐run price transmission parameters in world and neighbour countries for rice and coarse grains suggest that, in these select markets, there are either large transactions costs or quality premiums that vary systematically with border prices, and/or mark‐ups captured by traders with market power.     

A Heteroskedastic Multivariate Tobit Analysis of Price Dynamics in the Presence of Price Floors

This article presents an econometric analysis of the effects of price floors on price dynamics and price volatility in a multimarket context. We investigate the implications of a government price-support program providing a censoring mechanism to the price determination process. The analysis uses a dynamic multivariate Tobit model under time-varying volatility. The model is applied to the U.S. dairy markets with a special focus on the effects of government price-support programs in a period of market liberalization. The econometric analysis provides useful information on the multimarket effects of price supports on price dynamics and price volatility.     

中加菜籽油期货市场波动溢出实证研究

利用误差修正模型、BEKK-GARCH模型和格兰杰因果关系实证研究了加拿大和中国菜籽油期货市场之间的信息传导、波动溢出和价格引导关系。实证结果显示：这两个市场之间存在一定的信息传导关系;加拿大菜籽油期货市场对中国菜籽油期货市场存在显著的波动溢出效应,而中国菜籽油期货市场对加拿大菜籽油期货市场的波动溢出不显著;短期内加拿大菜籽油期货市场对中国菜籽油期货市场的价格引导作用更强些,这与加拿大菜籽油期货市场是全球菜籽油定价中心的实际相吻合,而中国菜籽油期货市场的竞争力有待进一步提升。     

Marketing and Pricing Dynamics in the Presence of Structural Breaks: The Hungarian Pork Market

The study of marketing margins and price transmission on various commodity markets has been a popular research topic of the past decades (see Meyer & Von Cramon-Taubadel, 2004 Meyer , J. , & Von Cramon-Taubadel , S. ( 2004 ). Asymmetric price transmission: A survey . Journal of Agricultural Economics , 55 ( 3 ), 581 – 611 .[Crossref], [Web of Science ®] , [Google Scholar], for a recent survey). However, with a few exception these studies focused on developed economies. This article examines this phenomena on the Hungarian pork market. The Johansen (maximum likelihood, 1988 Johansen , S. ( 1988 ). Statistical analysis of cointegrating vectors . Journal of Economic Dynamics and Control , 12 , 231 – 254 .[Crossref], [Web of Science ®] , [Google Scholar]) or Engle and Granger (2-step, 1987 Engle , R. F. , & Granger , C. W. J. ( 1987 ). Cointegration and error correction: Representation, estimation and testing . Econometrica , 55 , 251 – 276 .[Crossref], [Web of Science ®] , [Google Scholar]) cointegration tests do not reject the no-cointegration null hypothesis between the Hungarian pork producer and retail price series. Therefore, we applied the Gregory and Hansen (1996 Gregory , A. W. , & Hansen , B. E. ( 1996 ). Residual-based tests for cointegration in models with regime shifts . Journal of Econometrics , 70 , 99 – 126 .[Crossref], [Web of Science ®] , [Google Scholar]) procedure with recursively estimated break points and Augmented Dickey Fuller (ADF) statistics and found that the prices are cointegrated with a structural break occurring in April 1996 Gregory , A. W. , & Hansen , B. E. ( 1996 ). Residual-based tests for cointegration in models with regime shifts . Journal of Econometrics , 70 , 99 – 126 .[Crossref], [Web of Science ®] , [Google Scholar]. Exogeneity tests reveal the causality running from producer to retail prices both in the long and short run. Homogeneity tests are rejected, suggesting a markup pricing strategy. Price transmission modeling suggests that price transmission on the Hungarian pork meat market is symmetric in the long run but asymmetric in the short run; that is, processors, wholesalers, or retailers might take temporary advantage should price changes occur.     

Impacts of Market Reform on Spatial Volatility of Maize Prices in Tanzania

Maize is one of the major staples and cash crops for many Tanzanians. Excessive volatility of maize prices destabilises farm income in maize‐growing regions and is likely to jeopardise nutrition and investment in many poor rural communities. This study investigates whether market reform policies in Tanzania have increased the volatility of maize prices, and identifies regional characteristics that can be attributed to the spatial price volatility. To achieve the objectives, an autoregressive conditional heteroskedasticity in mean (ARCH‐M) model is developed and estimated in this study. Results show that the reforms have increased farm‐gate prices and overall price volatility. Maize prices are lower in surplus and less developed regions than those in deficit and developed regions. Results also show that the developed and maize‐deficit regions, and regions bordering other countries have experienced less volatile prices than less developed, maize‐surplus and non‐bordering regions. Our findings indicate that investments in communication and transportation infrastructures from government and donor countries are likely to increase inter‐regional and international trade, thereby reducing the spatial price volatility in Tanzanian maize prices in the long run.     

供应链企业间合作机制的研究

随着市场经济的蓬勃发展,企业间的竞争形式也走向了多样化。近些年来,供应链思想作为一种全新的管理模式与管理思想也逐步得到了管理界的认可。在这种形势下,如何协调供应链中的合作关系,构建供应链的合作关系机制,成为供应链研究的重要命题。论述要通过建立供应链合作机制,在供应链内部实现信息共享、利润分配、风险共担,最终通过整个供应链的竞争力的提升而达到供应链上的企业共赢的局面。